recipes-kernel/linux/files/0004-i2c-npcm-Modify-the-client-address-assignment.patch

From c27d35d1759112aab19c289b79f5f499f8c71ff5 Mon Sep 17 00:00:00 2001
From: Tyrone Ting <kfting@nuvoton.com>
Date: Tue, 1 Oct 2024 14:28:53 +0800
Subject: [PATCH 4/6] i2c: npcm: Modify the client address assignment

Store the client address earlier since it might get called in
the i2c_recover_bus() logic flow at the early stage of
npcm_i2c_master_xfer().

Upstream-Status: Pending [https://patchwork.ozlabs.org/project/linux-i2c/list/?series=426080]
Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
Reviewed-by: Tali Perry <tali.perry1@gmail.com>
---
 drivers/i2c/busses/i2c-npcm7xx.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index 7ed4306854cd..c4c68a9242c0 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -2153,6 +2153,19 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 
 	} while (time_is_after_jiffies(time_left) && bus_busy);
 
+	/*
+	 * Previously, the address was stored w/o left-shift by one bit and
+	 * with that shift in the following call to npcm_i2c_master_start_xmit().
+	 *
+	 * Since there are cases that the i2c_recover_bus() gets called at the
+	 * early stage of npcm_i2c_master_xfer(), the address is stored with
+	 * the shift and used in the i2c_recover_bus().
+	 *
+	 * The address is stored from bit 1 to bit 7 in the register for
+	 * sending the i2c address later so it's left-shifted by 1 bit.
+	 */
+	bus->dest_addr = slave_addr << 1;
+
 	/*
 	 * Check the BER (bus error) state, when ber_state is true, it means that the module
 	 * detects the bus error which is caused by some factor like that the electricity
@@ -2170,7 +2183,6 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	}
 
 	npcm_i2c_init_params(bus);
-	bus->dest_addr = slave_addr;
 	bus->msgs = msgs;
 	bus->msgs_num = num;
 	bus->cmd_err = 0;
-- 
2.46.1.824.gd892dcdcdd-goog